Mellow Column - Columella columella
A small shell, to 1.6 mm diameter and 2.9 mm in height, subcylindrical (pupiform) with course and irregular incremental striae, about 6 to 7 whorls, the last or second to last whorl before the aperture smaller than the adjacent whorls (giving a slightly pinched profile). Shell coloration is translucent brown to reddish-brown. Aperture is ovate, the lip unthickened and without teeth (denticles); periphery rounded; umbilicus very small (Hendricks 2012, Burke 2013). Internal anatomy is described by Pokryszko (1990).
Columella differs from all other mature shells of similar size and shape by lacking teeth in the aperture, absence of an external crest behind the aperture, and aperture round with a thin lip. C. columella differs from C. edentula by being distinctly more cylindrical instead of clearly tapering to the apex, with 6-7 whorls instead of 5-6, the penultimate whorl before the aperture slightly pinched (smaller) than adjacent whorls instead of with last whorl larger than preceding whorl, height to about 3.0 mm instead of 2.7 mm. Small juveniles resemble Punctum, and can be confused with toothless juvenile Vertigo.
Circumboreal across higher latitudes and elevations; in western North America south to Arizona and New Mexico. In Montana, reported east of the Continental Divide from two counties: Gallatin and Madison. Elevation range is 1777 to 2027 m (5830 to 6650 ft). Reports of this species by Vanatta for Ravalli County were considered by Henderson to be Columella edentula. Range and abundance in Montana poorly defined; current status needs investigation. May be locally relatively common; 10 individuals were reported at one Madison County site in late October (Hendricks 2012).
Observations in Montana Natural Heritage Program Database
Number of Observations:
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Map Help and Descriptions
(Observations spanning multiple months or years are excluded from time charts)
Predicted Distribution in Montana
Predicted distribution model for Mellow Column (Columella columella)
Records were spatially unique and had a locational uncertainty of ≤ 400 meters.
Hotter colors indicate areas that are predicted to have more suitable habitat for the species.
Black dots are positive data used to build the model.
Gray dots are locations where a survey capable of detecting the species has been performed.
Landownership, a shaded relief map, and county lines are included for reference.
Details of the modeling effort, a description of the environmental layers used, and a more thorough interpretation
of model outputs can be found in the report Land Mollusk Surveys and Predicted Distribution Models on USFS Northern Region Lands: 2007
More model output for this species
Moist forested sites, aspen pockets, moist open meadows. Canopy species include Douglas-fir, Engelmann spruce, subalpine fir, limber pine, and aspen. Found under woody debris, on logs, vegetation, bryophyte mats, and in leaf litter (Hendricks 2012).
- Literature Cited AboveLegend: View Online Publication
- Burke, T. E. 2013. Land snails and slugs of the Pacific Northwest. Corvallis, OR: Oregon State University Press. 344 p.
- Hendricks, P. 2012. A Guide to the Land Snails and Slugs of Montana. A report to the U.S. Forest Service - Region 1. Montana Natural Heritage Program, Helena, MT. vii + 187 pp. plus appendices.
- Pokryszko, B.M. 1990. The Vertiginidae of Poland (Gastropoda: Pulmonata: Pupilloidae) – a systematic monograph. Polska Akademia Nauk Instytut Zoologii, Annales Zoologici 43:133-257.
- Additional ReferencesLegend: View Online Publication
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- Beetle, D.E. 1989. Checklist of recent Mollusca of Wyoming, U.S.A. The Great Basin Naturalist 49(4):637-645.
- Forsyth, R.G. 2004. Land snails of British Columbia. Royal British Columbia Museum: Victoria, British Columbia, Canada. 188 pp.
- Frest, T.J. and E.J. Johannes. 2001. An annotated checklist of Idaho land and freshwater mollusks. Journal of the Idaho Academy of Science 36(2):1-51.
- Henderson, J. 1924. Mollusca of Colorado, Utah, Montana, Idaho, and Wyoming. University of Colorado Studies 13(2):65-223.
- Pilsbry, H.A. 1948. Land Mollusca of North America (north of Mexico), Volume II Part 2. The Academy of Natural Sciences of Philadelphia Monograph Number 2(2): 521-1113.
- Vanatta, E.G. 1914. Montana shells. Proceedings of the Academy of Natural Sciences of Philadelphia 66:367-371.
- Additional Sources of Information Related to "Snails / Slugs"